The present invention relates to a process for controlling a flow amount of cooling fluid flowing through the internal combustion engine and an apparatus thereof.
At present, as commercially available cooling systems for engines, most of the systems are types, which cool the engines by water-cooling. The water-cooled system prevents overheating due to the heating of the engine and prevents overcooling of the engine in cold times, always keeping the engine at an optimal temperature
In the cooling system by water-cooling, a radiator is placed outside of an engine, and the radiator and the engine are connected by means of a rubber hose, etc. to circulate a cooling fluid. The main configuration of the water-cooled system is composed of the radiator, which plays a role as a heat exchanger, a water pump, which forcedly feeds the cooling fluid from the engine to the radiator, a thermostat, which controls the flow of the cooling fluid to or from the radiator depending upon a change in the temperature of the cooling fluid to keep the temperature of the cooling fluid at an optimal level, and a rubber hose, which forms a circulation channel for the cooling fluid, and the like. Such a water-cooled system for cooling an engine is utilized in an engine for a two-wheeled vehicle as well as an engine for four-wheeled vehicle.
In recent vehicles, the weight is attached to the design for the outward appearance and, thus, it is required for the apparatuses to be placed within the engine room to improve the design of the apparatuses making it possible to effective layout within the engine room. For example, with regard to the radiator, there is a down-flow type radiator having an upper tank and a lower tank placed therein which carries out the heat exchange by circulating the cooling fluid. Due the configuration where the flow of the cooling fluid in the vertical direction, the down-flow type radiator is not suitable to be fit to a vehicle having a low hood. In the case of the vehicle having a low hood, a cross flow type radiator is utilized in which the cooling fluid flows in the horizontal direction. The cross flow type radiator can adjust the height and, thus can be adapted to the design of the vehicle having a low hood.
As described above, the thermostat for controlling the flow of the cooling fluid is placed within the four-wheeled vehicle having the water-cooled engine. As shown in FIG. 6, a thermostat 1xe2x80x2 which is utilized in a general vehicle is placed on an appropriate portion of a cooling fluid channel 3xe2x80x2 formed between the body of an engine E and a radiator R. The thermostat 1xe2x80x2 itself is accommodated within a case or such. As a mechanism for quickly increasing the temperature of the cooling fluid to the optimum temperature at the time of starting the engine, some of the thermostats have a configuration to place a bypass channel 3Axe2x80x2 on a cooling fluid channel 3xe2x80x2. Many thermostats 1xe2x80x2 have been developed having a bypass valve construction accommodated within the thermostat 1xe2x80x2 in order to bypass the cooling fluid to the bypass channel 3Axe2x80x2.
Depending upon the design of the vehicle, there is a vehicle having an extremely small space within the engine room. In the case of such a vehicle, the piping positions of the cooling fluid channel 3xe2x80x2 and the bypass channel 3Axe2x80x2 are regulated, and the position of the thermostat 1xe2x80x2 accommodated within the case or such to be placed is also regulated.
With regard to the two-wheeled vehicle having the water-cooled engine carried therein, the space is further smaller, and the positions of the piping of the cooling fluid channel 3xe2x80x2, the bypass channel 3Axe2x80x2, and the thermostat 1xe2x80x2 are also regulated similar to or much more than the case of the four-wheeled vehicle.
As shown in FIG. 7, the conventional thermostat 1xe2x80x2 is placed within the cooling fluid 3xe2x80x2 and a piston 16xe2x80x2 is moved forward and backward in the direction parallel to the flow of the cooling fluid to open or close a thermo-valve 12xe2x80x2. The flow amount of the cooling fluid flowing at the position where the thermostat 1xe2x80x2 is placed should be secured to be approximately the same degree as the flow amount of the cooling fluid flowing within another portions. For this reason, it is required to secure a capacity for the flow of the cooling fluid at a lower portion of the thermo-valve 12xe2x80x2 (around the wax case 15xe2x80x2). Specifically, the pipe diameter (cross section) of the cooling fluid channel 3xe2x80x2 at the portion on which the thermostat 1xe2x80x2 is placed should be larger than the pipe diameter (cross section) of the cooling fluid channel 3xe2x80x2 at any other portion.
In the thermostat 1xe2x80x2 shown in FIG. 7, since the wax case 15xe2x80x2, which detects the change in the temperature, is in the state of being directly immersed in the cooling fluid, it sensitively responds to the change in the temperature of the cooling fluid. For this reason, when the temperature of the cooling fluid is not uniform, for example, in the case of the warm-up of the engine at a cold morning, the thermo-valve 12xe2x80x2 is frequently opened or closed to sometimes cause a hunting phenomenon. If the hunting phenomenon is caused, the flow amount of the cooling fluid cannot be controlled in a stable manner, and the temperature of the engine E cannot be held at the optimal temperature. As a result, the fuel ratio is changed for the worse and a large amount of harmful exhaust gas is discharged.
An object of the present invention is to provide a process for controlling a flow of a cooling fluid, which can secure an adequate flow amount of the cooling fluid without changing the pipe diameter of the existing cooling fluid channel, and which can prevent the worsening of the fuel ratio and the discharge of the harmful exhaust gas due to the hunting phenomenon, and an apparatus thereof
A flow control process for controlling a cooling fluid according to the present invention, which can attain the object described above, is a process for controlling a cooling fluid flowing through a cooling fluid channel of an internal combustion engine, which comprises, moving an valve element forward or backward in the manner of crossing the cooling fluid channel according to a change in the temperature of the cooling fluid so as to communicate or block the cooling fluid channel.
In the flow control process for controlling a cooling fluid, since the valve element is moved forward or backward in the manner of crossing the cooling fluid channel, the flow amount of the cooling fluid can be secured without changing the pipe diameter of the cooling fluid channel and the device can be fit to a voluntary portion of the cooling fluid channel.
The flow controller according to the present invention, which attains the object is placed within a cooling fluid channel of an internal combustion engine and controls a flow of a cooling fluid flowing through the cooling fluid channel depending upon the change in the temperature of the cooling fluid and comprises: a cylindrical valve body which has an inlet opening and an outlet opening formed on a circumference thereof and which is fixed on the position where said inlet opening and said outlet opening are communicated with said cooling fluid channel; a fluid channel area which communicates said inlet opening and said outlet opening within said valve body, and a valve element which moves forward and backward in the manner of crossing said channel area depending upon the change in the temperature of said cooling fluid, whereby said inlet opening and said outlet opening are opened or closed through the movement of said valve element to communicate or block said fluid channel area,
According to the flow controller for controlling a cooling fluid, since the valve element is configured so as to move forward or backward in the manner of crossing the fluid channel area, the flow amount of the cooling fluid can be secured without changing the pipe diameter of the cooling fluid channel and the controller can be fit to a voluntary portion of the cooling fluid channel.
In the flow controller of the cooling fluid described above, said valve element moves forward or backward due to the expansion/shrinkage of a thermal expanding element, and the change in the temperature of the cooling fluid is transmitted to said thermo-sensitive portion via the valve element.
Since the change in the temperature is transmitted to the thermosensitive portion via the valve element, the thermal expanding element within the thermo-sensitive portion responds to the change in the temperature of the cooling fluid in a mild manner, which prevents the hunting phenomenon.
Furthermore, in the flow controller of the cooling fluid described above, a joint cover for fixing said valve body is unified with said valve body.
The unification of the valve body with the joint cover makes it easy to place the flow controller of the cooling fluid within the cooling fluid channel.
Moreover, in the flow controller of the cooling fluid described above, a bypass opening is formed on the circumference of said valve body, and said bypass opening and a bypass channel are communicated or blocked due to the movement of the valve element.
In this embodiment, due to the movement of the valve element, the main channel of the cooling fluid channel is communicated or blocked, and the bypass opening and a bypass channel are communicated or blocked.
For this reason, the cooling fluid can be controlled by a bypass channel only by a very simple structure.